The present invention relates to the art of electroplating and particularly to the art of electroplating small articles, for example small metallic parts used as contacts in the electronics industry and more particularly to the art of goldplating electronic components.
The growth and increased sophistication of the electronics industry has led to the need for electroplated components and particularly contacts of various description electroplated priamarily with gold to prevent corrosion and erosion of contact areas and maintain reliable electrical conductivity of the components.
Gold has become recognized as the leading plating material because of its relative unalterability, good solderability and low contact resistance.
In some cases plating of such contacts has been accomplished by so called "barrel plating" techniques where the articles are tumbled in a barrel as the plating is applied.
Such techniques are expensive because of the increased price of gold coupled with the use of excess material because such techniques lead to plating unnecessary areas and overplating. Accordingly, the use of techniques to plate only contact surfaces have come to be appreciated.
One prior art arrangement for selective plating is shown in U.S. Pat. No. 3,904,489 which utilizes a porous felt type applicator which is used to apply the electroplating solution to the parts which are carried by a continuous belt by insertion therethrough.
Another prior art arrangement which is an improvement in the aforenoted arrangement is shown in U.S. Pat. No. 3,966,581.
Still another prior art arrangement is shown in U.S. Pat. No. 4,155,815-Francis, et al. where endless tractor belts are utilized to hold printed circuit boards for selective electroplating.
No prior art devices are known to accomplish continuous electroplating of selected articles where the articles are continuously carried in selected orientation through electroplating bath to electroplate only selected portions thereof while electrical contact is maintained between internal from a contact strip in contact with a first portion of the article while the downwardly depending portion of the article to be electroplated is immersed in the electroplating solution.